Monoclonal antibodies (mAbs) are important protein-based therapeutics for treating various human diseases such as cancer, infectious diseases, inflammation, and autoimmune diseases. More than 20 mAb products have been approved by the U.S. Food and Drug Administration (FDA), and approximately 20% of all biopharmaceuticals currently being evaluated in clinical trials are mAbs (Daugherty et al., Adv. Drug Deliv. Rev. 58:686-706, 2006; and Buss et al., Curr. Opinion in Pharmacol. 12:615-622, 2012).
mAb-based therapies are usually administered repeatedly over an extended period of time and require several mg/kg dosing. Antibody solutions or suspensions can be administered via parenteral routes, such as by intravenous (IV) infusions, and subcutaneous (SC) or intramuscular (IM) injections. The SC or IM routes reduce the treatment cost, increase patient compliance, and improve convenience for patients and healthcare providers during administration compared to the IV route. To be effective and pharmaceutically acceptable, parenteral formulations should preferably be sterile, stable, injectable (e.g., via a syringe), and non-irritating at the site of injection, in compliance with FDA guidelines. Because of the small volumes required for subcutaneous (usually under about 2 mL) and intramuscular (usually under about 5 mL) injections, these routes of administration for high-dose protein therapies require concentrated protein solutions. These high concentrations often result in very viscous formulations that are difficult to administer by injection, cause pain at the site of injection, are often imprecise, and/or may have decreased chemical and/or physical stability.
These characteristics result in manufacturing, storage, and usage requirements that can be challenging to achieve, in particular for formulations having high concentrations of high-molecular-weight proteins, such as mAbs. All protein therapeutics to some extent are subject to physical and chemical instability, such as aggregation, denaturation, crosslinking, deamidation, isomerization, oxidation, and clipping (Wang et al., J. Pharm. Sci. 96:1-26, 2007). Thus, optimal formulation development is paramount in the development of commercially viable protein pharmaceuticals.
High protein concentrations pose challenges relating to the physical and chemical stability of the protein, as well as difficulty with manufacture, storage, and delivery of the protein formulation. One problem is the tendency of proteins to aggregate and form particulates during processing and/or storage, which makes manipulations during further processing and/or delivery difficult. Concentration-dependent degradation and/or aggregation are major challenges in developing protein formulations at higher concentrations. In addition to the potential for non-native protein aggregation and particulate formation, reversible self-association in aqueous solutions may occur, which contributes to, among other things, increased viscosity that complicates delivery by injection. (See, for example, Steven J. Shire et al., J. Pharm. Sci. 93:1390-1402, 2004.) Increased viscosity is one of the key challenges encountered in concentrated protein compositions affecting both production processes and the ability to readily deliver such compositions by conventional means. (See, for example, J. Jezek et al., Advanced Drug Delivery Reviews 63:1107-1117, 2011.)
Highly viscous liquid formulations are difficult to manufacture, draw into a syringe, and inject subcutaneously or intramuscularly. The use of force in manipulating the viscous formulations can lead to excessive frothing, which may further denature and inactivate the therapeutically active protein. High viscosity solutions also require larger diameter needles for injection and produce more pain at the injection site.
Currently available commercial mAb products administered by SC or IM injection are usually formulated in aqueous buffers, such as a phosphate or L-histidine buffer, with excipients or surfactants, such as mannitol, sucrose, lactose, trehalose, POLOXAMER® (nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethylene oxide))) or POLYSORBATE® 80 (PEG(80)sorbitan monolaurate), to prevent aggregation and improve stability. Reported antibody concentrations formulated as described above are typically up to about 100 mg/mL (Wang et al., J. Pharm. Sci. 96:1-26, 2007).
U.S. Pat. No. 7,758,860 describes reducing the viscosity in formulations of low-molecular-weight proteins using a buffer and a viscosity-reducing inorganic salt, such as calcium chloride or magnesium chloride. These same salts, however, showed little effect on the viscosity of a high-molecular-weight antibody (IMA-638) formulation. As described in U.S. Pat. No. 7,666,413, the viscosity of aqueous formulations of high-molecular-weight proteins has been reduced by the addition of such salts as arginine hydrochloride, sodium thiocyanate, ammonium thiocyanate, ammonium sulfate, ammonium chloride, calcium chloride, zinc chloride, or sodium acetate in a concentration of greater than about 100 mM or, as described in U.S. Pat. No. 7,740,842, by addition of organic or inorganic acids. However, these salts do not reduce the viscosity to a desired level and in some cases make the formulation so acidic that it is likely to cause pain at the site of injection.
U.S. Pat. No. 7,666,413 describes reduced-viscosity formulations containing specific salts and a reconstituted anti-IgE mAb, but with a maximum antibody concentration of only up to about 140 mg/mL. U.S. Pat. No. 7,740,842 describes E25 anti-IgE mAb formulations containing acetate/acetic acid buffer with antibody concentrations up to 257 mg/mL. The addition of salts such as NaCl, CaCl2, or MgCl2 was demonstrated to decrease the dynamic viscosity under high-shear conditions; however, at low-shear the salts produced an undesirable and dramatic increase in the dynamic viscosity. Additionally, inorganic salts such as NaCl may lower solution viscosity and/or decrease aggregation (EP 1981824).
Non-aqueous antibody or protein formulations have also been described. WO2006/071693 describes a non-aqueous suspension of up to 100 mg/mL mAb in a formulation having a viscosity enhancer (polyvinylpyrrolidone, PVP) and a solvent (benzyl benzoate or PEG 400). WO2004/089335 describes 100 mg/mL non-aqueous lysozyme suspension formulations containing PVP, glycofurol, benzyl benzoate, benzyl alcohol, or PEG 400. US2008/0226689A1 describes 100 mg/mL human growth hormone (hGH) single phase, three vehicle component (polymer, surfactant, and a solvent), non-aqueous, viscous formulations. U.S. Pat. No. 6,730,328 describes non-aqueous, hydrophobic, non-polar vehicles of low reactivity, such as perfluorodecalin, for protein formulations. These formulations are non-optimal and have high viscosities that impair processing, manufacturing and injection; lead to the presence of multiple vehicle components in the formulations; and present potential regulatory challenges associated with using polymers not yet approved by the FDA.
Alternative non-aqueous protein or antibody formulations have been described using organic solvents, such as benzyl benzoate (Miller et al., Langmuir 26:1067-1074, 2010), benzyl acetate, ethanol, or methyl ethyl ketone (Srinivasan et al., Pharm. Res. 30:1749-1757, 2013). In both instances, viscosities of less than 50 centipoise (cP) were achieved upon formulation at protein concentrations of at least about 200 mg/mL. U.S. Pat. No. 6,252,055 describes mAb formulations with concentrations ranging from 100 mg/mL up to 257 mg/mL. Formulations with concentrations greater than about 189 mg/mL demonstrated dramatically increased viscosities, low recovery rates, and difficulty in processing. U.S. Patent Application Publication No. 2012/0230982 describes antibody formulations with concentrations of 100 mg/mL to 200 mg/mL. None of these formulations are low enough viscosity for ease of injection.
Du and Klibanov (Biotechnology and Bioengineering 108:632-636, 2011) described reduced viscosity of concentrated aqueous solutions of bovine serum albumin with a maximum concentration up to 400 mg/mL and bovine gamma globulin with a maximum concentration up to 300 mg/mL. Guo et al. (Pharmaceutical Research 29:3102-3109, 2012) described low-viscosity aqueous solutions of four model mAbs achieved using hydrophobic salts. The mAb formulation employed by Guo had an initial viscosity, prior to adding salts, no greater than 73 cP. The viscosities of many pharmaceutically important mAbs, on the other hand, can exceed 1,000 cP at therapeutically relevant concentrations.
It is not a trivial matter to control aggregation and viscosity in high-concentration mAb solutions (EP 2538973). This is evidenced by the few mAb products currently on the market as high-concentration formulations (>100 mg/mL) (EP 2538973).
The references cited above demonstrate that while many groups have attempted to prepare low-viscosity formulations of mAbs and other therapeutically important proteins, a truly useful formulation for many proteins has not yet been achieved. Notably, many of the above reports employ agents for which safety and toxicity profiles have not been fully established. These formulations would therefore face a higher regulatory burden prior to approval than formulations containing compounds known to be safe. Indeed, even if a compound were to be shown to substantially reduce viscosity, the compound may ultimately be unsuitable for use in a formulation intended for injection into a human.
Many pharmaceutically important high-molecular-weight proteins, such as mAbs, are currently administered via IV infusions in order to deliver therapeutically effective amounts of protein due to problems with high viscosity and other properties of concentrated solutions of large proteins. For example, to provide a therapeutically effective amount of many high-molecular-weight proteins, such as mAbs, in volumes less than about 2 mL, protein concentrations greater than 150 mg/mL are often required.
It is, therefore, an object of the present invention to provide concentrated, low-viscosity liquid formulations of pharmaceutically important proteins, especially high-molecular-weight proteins, such as mAbs.
It is a further object of the present invention to provide concentrated low-viscosity liquid formulations of proteins, especially high-molecular-weight proteins, such as mAbs, capable of delivering therapeutically effective amounts of these proteins in volumes useful for SC and IM injections.
It is a further object of the present invention to provide the concentrated liquid formulations of proteins, especially high-molecular-weight proteins, such as mAbs, with low viscosities that can improve injectability and/or patient compliance, convenience, and comfort.
It is also an object of the present invention to provide methods for making and storing concentrated, low-viscosity formulations of proteins, especially high-molecular-weight proteins, such as mAbs.
It is an additional object of the present invention to provide methods of administering low-viscosity, concentrated liquid formulations of proteins, especially high-molecular-weight proteins, such as mAbs. It is an additional object of the present invention to provide methods for processing reduced-viscosity, high-concentration biologics with concentration and filtration techniques known to those skilled in the art.